Add an updated version of the pdf document
Update list with a recently added record type
Bump dicom dependency
Handle extended ascii characters

While officially the RTPConnect standard may specify its encoding as
ASCII only, in reality the text file and applications that use it (e.g.
Mosaiq) can support the extended ascii character set, also known as
ISO8859-1 (which gives a total of 256 characters in 8 bits).

This commit enables the library to properly handle both values and file
read/write with ISO8859-1 encoding.
Gem release version 1.4